Wireless control system, control device, controllable device device control method, control program, and computer readable recording medium containing the same

ABSTRACT

The wireless control system of the present invention constitutes a wireless AV system ( 101 ) which forms a wireless transmission network ( 1 ) in which a wireless center unit ( 102 ) and a TV main body unit ( 103 ) are connected with each other by a wireless LAN. The wireless center unit ( 102 ) transmits to the TV main body unit ( 103 ) control data having, in a control command, a discrimination code for discriminating between devices in the wireless AV system ( 101 ). The TV main body unit ( 103 ) reads out the discrimination code included in the received control data, discriminates a device to carry out the control command included in the control data, and transmits the control data to the discriminated device. As a result, even when the number of controlled devices that a controlling device has to control increases, a throughput of the controlling device for discrimination of control data does not increase, and therefore the whole system constituted of the controlling device and the controlled devices can be smoothly operated.

TECHNICAL FIELD

The present invention relates to: a wireless control system constitutedof a controlling device and controlled devices that are wirelesslycontrolled by the controlling device; a controlling device; controlleddevices; method of controlling devices; a control program; and a storagemedium readable by a computer, for storing the program.

BACKGROUND ART

Recently, with the explosive prevalence of the Internet, a LAN (LocalArea Network) is frequently constructed in offices, houses and the like.

Because cable wiring is troublesome, there is an increasing need for socalled wireless LANs which construct a LAN wirelessly, which is aided byprogress in digital wireless communication technologies. Further,wireless communication devices which constitute such a wireless LAN areexpected to be used in large numbers, because the devices can be used inmobile terminals, such as notebook computers in mobile environments.

As a representative technology of the wireless LAN, there is IEEE 802.11which has already been standardized by IEEE (Institute of Electrical andElectronics Engineers). This standardized technology defines from aphysical layer to a MAC (Media Access Control) layer, being a lowerlayer of a data link in an OSI model, and can be replaced with Ethernet™which is a wired LAN transmission channel. Further, IEEE 802.11 canprovide a roaming function as an additional function due to beingwireless.

Recently, in order to transmit/receive video image data or audio datawirelessly, a wireless AV system using such a wireless LAN is proposed.

Generally, a wireless AV system has a problem that video image data tobe transmitted/received deteriorates due to transmission errors.

Patent Document 1 (PCT international publication No. WO 01/006795(publication date; Jan. 25, 2001)) discloses an image decoding method inwhich a transmission error is detected by an image header included invideo image data, and when a transmission error is detected, video imagedata is temporarily stored, repetition of a header different from theimage header is detected, and based on this repeated header, temporarilystored video image data is decoded, and thereby deterioration of thevideo image data is prevented.

In a conventional wireless AV system, when one controlling device (suchas an AV amplifier) controls a plurality of controlled devices (such asa video deck, a DVD player, a stereo, and a TV), the controlling devicetransmits control data by wireless to each of the controlled devices.Namely, the controlling device causes a data transmitting/receiving unitthereof to sort and transmit control data to each of the controlleddevices.

As a result, the more controlled devices one controlling device has tocontrol, the larger throughput is necessary for sorting of control dataitems in a data transmitting/receiving unit included in the controllingdevice, that is, the larger throughput is necessary for discriminatingcontrol data items, which makes it difficult for the controlling deviceto promptly control the controlled devices, with a result that the wholeof the wireless AV system does not operate smoothly.

The present invention is made in view of the foregoing problems, and itsobject is to realize a wireless control system in which, even when thenumber of controlled devices which the controlling device has to controlincreases, a throughput for discriminating control data in thecontrolling side does not increase, and the whole of the wireless AVsystem can be smoothly operated.

DISCLOSURE OF INVENTION

In order to solve the foregoing problem, the wireless control system ofthe present invention is constituted of a controlling device andcontrolled devices that are wirelessly controlled by the controllingdevice, wherein the controlling device wirelessly transmits control datato the controlled devices, the control data having, in a control commandfor controlling the controlled devices, a discrimination code fordiscriminating between a controlled device to which the control commandis to be transmitted and other one or more controlled devices in thesystem, the controlled devices receive the control data transmittedwirelessly from the controlling device, read out the discrimination codeincluded in the received control data, discriminate a controlled deviceto carry out the control command included in the control data, andtransmit the control data to the discriminated controlled device.

Further, the wireless control system is constituted of a controllingdevice and controlled devices that are wirelessly controlled by thecontrolling device, wherein the controlling device includes (i) acontrol data generating section for generating control data having, in acontrol command for controlling the controlled devices, a discriminationcode for discriminating between a controlled device to which the controlcommand is to be transmitted and other one or more controlled devices inthe system, and (ii) a wireless communication section for transmittingthe control data transmitted from the control data generating section,to a controlled device with which the wireless communication section isin communication, and the controlled devices include (i) a wirelesscommunication section for receiving the control data from thecontrolling device, (ii) a discrimination section for reading out thediscrimination code included in the received control data anddiscriminating a controlled device to carry out the control commandincluded in the control data, and (iii) a control data transmissionsection for transmitting the control data to the controlled devicediscriminated by the discrimination section.

With these arrangements, the controlling device generates control datahaving, in a control command, a discrimination code for discriminatingbetween the controlled devices, and the controlled devices use thecontrol data so as to perform discrimination of control data. As aresult, even when the number of controlled devices to be controlled byone controlling device increases, a throughput for discriminatingcontrol data in the controlling device does not increase.

Therefore, even when the number of the controlled devices increases, theburden of data processing in the controlling device does not increase,so that the controlling device can promptly control each of thecontrolled devices. As a result, the whole of the wireless AV system canbe operated smoothly.

The control data generating section may be arranged so that whengenerated control data includes the same data as a predetermined keycode, the control data generating section performs a predeterminedconversion of the same data, and transmits the converted control data tothe wireless communication section.

In this case, misidentification of a discrimination code can be avoided,so that the controlling device can always control a suitable controlleddevice.

Control data generated in the control data generating section may be anyone of control data to be transmitted to a control section included inthe controlling device, control data to be transmitted to the wirelesscommunication section in the controlling device, control data to betransmitted to a control section included in the controlled devices, andcontrol data to be transmitted to the wireless communication section inthe controlled devices.

Further, the control data may include, as a control command, a commandfor performing a change of a data transmission rate, a change of awireless communication channel, a change of a tuner channel, switchingof an input, and acquisition of a communication state.

Further, the controlled devices of the wireless control system may bearranged as follows.

The controlled devices according to the present invention may bearranged so as to be included in a wireless control system constitutedof a controlling device and controlled devices that are wirelesslycontrolled by the controlling device, the controlled devices (i)receiving control data which includes a discrimination code fordiscriminating between the controlled devices in the system, and (ii)discriminating a controlled device to carry out a control commandincluded in the control data, based on the discrimination code includedin the received control data.

Further, the controlled devices according to the present invention maybe arranged so as to be included in a wireless control systemconstituted of a controlling device and controlled devices that arewirelessly controlled by the controlling device, the controlled devicesincluding (i) a wireless communication section for receiving from thecontrolling device control data including a discrimination code fordiscriminating between the controlled devices in the system, (ii) adiscrimination section for reading out a discrimination code included inthe received control data and discriminating a controlled device tocarry out a control command included in the control data, and (iii) acontrol data transmission section for transmitting the control data tothe controlled device discriminated by the discrimination section.

Further, the controlling device of the wireless control system may bearranged as follows.

The controlling device according to the present invention may bearranged so as to be included in a wireless control system constitutedof a controlling device and controlled devices that are wirelesslycontrolled by the controlling device, the controlling device wirelesslytransmitting control data to the controlled devices, the control datahaving, in a control command for controlling the controlled devices, adiscrimination code for discriminating between a controlled device towhich the control command is to be transmitted and other one or morecontrolled devices in the system.

Further, the controlling device according to the present invention maybe arranged so as to be included in a wireless control systemconstituted of a controlling device and controlled devices that arewirelessly controlled by the controlling device, the controlling deviceincluding (i) a control data generating section for generating controldata having, in a control command for controlling the controlleddevices, a discrimination code for discriminating between a controlleddevice to which the control command is to be transmitted and other oneor more controlled devices in the system, and (ii) a wirelesscommunication section for transmitting the control data transmitted fromthe control data generating section, to a controlled device with whichthe wireless communication section is in communication.

As the wireless communication section, a communication section thattransmits control data using a spread spectrum wireless system ispreferably used.

Further, as the wireless communication section, a communication sectionthat performs low power, close range, two-way wireless communicationsuch as a wireless LAN, Bluetooth or UWB (Ultra Wide Band) is preferablyused.

Note that the wireless control system may be realized by a computer. Inthis case, a storage medium readable by a computer, for storing acontrol program which realizes the wireless control system using acomputer by causing the computer to function as each of the sections, isalso within the scope of the present invention.

For a fuller understanding of the nature and advantages of theinvention, reference should be made to the ensuing detailed descriptiontaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a main structure of a wireless AVsystem according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a main structure of a wirelesscenter unit constituting the wireless AV system illustrated in FIG. 1.

FIG. 3 is a block diagram illustrating a main structure of a TV mainbody unit constituting the wireless AV system illustrated in FIG. 1.

FIG. 4( a) is a schematic diagram illustrating one example oftransmission/reception of a control command between the wireless centerunit and the TV main body unit.

FIG. 4( b) is a schematic diagram illustrating another example oftransmission/reception of a control command between the wireless centerunit and the TV main body unit.

FIG. 4( c) is a schematic diagram illustrating a further example oftransmission/reception of a control command between the wireless centerunit and the TV main body unit.

FIG. 5 is a figure illustrating one example of a key code included incontrol data in the wireless AV system illustrated in FIG. 1.

FIG. 6 is a figure illustrating one example of a data format of acontrol command transmitted/received in the wireless AV systemillustrated in FIG. 1.

FIG. 7( a) is a figure illustrating one example of conversion of controldata, according to the conversion method and the data structure ofcontrol data.

FIG. 7( b) is a figure illustrating another example of conversion ofcontrol data, according to the conversion method and the data structureof control data.

FIG. 7( c) is a figure illustrating a further example of conversion ofcontrol data, according to the conversion method and the data structureof control data.

FIG. 7( d) is a figure illustrating a further example of conversion ofcontrol data, according to the conversion method and the data structureof control data.

FIG. 8( a) is a schematic diagram illustrating transmission/reception ofcontrol data in a case where acquisition of transmitted radio wavestrength at a wireless station is intended.

FIG. 8( b) is a figure illustrating a data structure of control data inthe transmission/reception of control data illustrated in FIG. 8( a).

FIG. 9( a) is a schematic diagram illustrating transmission/reception ofcontrol data in a case where acquisition of received radio wave strengthat a wireless station is intended.

FIG. 9( b) is a figure illustrating a data structure of control data inthe transmission/reception of control data illustrated in FIG. 9( a).

FIG. 10( a) is a schematic diagram illustrating transmission/receptionof control data in a case where switching of an external input in acontrolled device is intended.

FIG. 10( b) is a figure illustrating a data structure of control data inthe transmission/reception of control data illustrated in FIG. 10( a).

FIG. 11( a) is a schematic diagram illustrating transmission/receptionof control data in a case where direct remote control of an externaldevice via a controlled device is intended.

FIG. 11( b) is a figure illustrating a data structure of control data inthe transmission/reception of control data illustrated in FIG. 11( a).

FIG. 12 is a figure illustrating a concrete example of the wireless AVsystem of the present invention.

FIG. 13 is a figure illustrating an applied example of the wireless AVsystem illustrated in FIG. 12.

BEST MODE FOR CARRYING OUT THE INVENTION

One embodiment of the present invention is described below withreference to the attached drawings. In the present embodiment, anexample in which the wireless controlling system of the presentinvention is applied to a wireless AV (audio visual) system isdescribed.

FIG. 1 is a block diagram illustrating a main structure of a wireless AVsystem 101 according to the present embodiment. Here, an example isillustrated in which the wireless AV system 101 is applied to a wirelessTV receiving device having a separable display, as illustrated in FIG.12.

That is, as illustrated in FIG. 12, the wireless AV system 101 isconstituted of a TV main body unit 103 and a wireless center unit 102.

The TV main body unit 103 has a wireless TV receiving device including abattery, and a remote controller 130. The remote controller 130 allowsremote control of a video deck or the like connected to the wirelesscenter unit 102 via the TV main body unit 103.

Further, the wireless center unit 102 is connected with antennas for BS,U/VHF and the like, and AV devices such as a DVD player and a videodeck, and image and/or audio data is wirelessly transmitted to the TVmain body unit 103.

The wireless AV system 101 is fully explained below. In the followingexplanation, “data” means all data items transmitted/received in ageneral wireless AV system 101, such as control data, image data, oraudio data.

As illustrated in FIG. 1, the wireless AV system 101 is constituted ofthe wireless center unit 102 as a base device and the TV main body unit103 as a portable terminal. A pair of the wireless center unit 102 andthe TV main body unit 103 constitutes a wireless transmission network 1.

The wireless center unit 102 and the TV main body unit 103 havefunctions of both a controlling device and a controlled device. That is,when the wireless center unit 102 functions as a controlling device, theTV main body unit 103 functions as a controlled device, and when the TVmain body unit 103 functions as a controlling device, the wirelesscenter unit 102 functions as a controlled device.

Here, in the wireless transmission network 1, data istransmitted/received between the wireless center unit 102 and the TVmain body unit 103 through a SS (Spread Spectrum) wireless system basedon the IEEE 802.11 standard.

The wireless center unit 102 includes antenna terminals (a BS(broadcasting satellite) terminal 11, a U/VHF antenna terminal 12, and adiversity terminal 13), a video 1 input terminal having an S terminal(external input 1) 14 for connecting a device such as a digital VTR orDVD player, a video 2 input terminal (external input 2) 15 for a decoderinput and a video 3 input terminal (external input 3) 16 which doublesas a monitor/BS output, and, provided as power sources, an AC powersource section 17 and Car-DC power source section 18.

Note that the wireless center unit 102 is fully explained later.

The TV main body unit 103 includes a video 4 input terminal (externalinput 4) 21, which doubles as a TV output, for connecting a device suchas a digital VTR or DVD (Digital Versatile Disc) player, and a powersource terminal (not shown) to be connected with an AC power sourcesection 22 and Car-DC power source section 23 which are provided aspower sources.

The TV main body unit 103 is a thin display device that is detachablefrom the wireless center unit 102 and is mobile or portable because of abuilt-in battery. The TV main body unit 103 is a broad concept includinga variety of display devices such as a liquid crystal TV, an inorganicEL (Electroluminescence)/organic EL display, or a plasma display, and isnot limited by its display mechanism.

Note that the TV main body unit 103 is fully explained later.

In the present embodiment, the TV main body unit 103 mainly includes adisplay function, an audio function and the like, and on the other handthe wireless center unit 102 mainly includes a controlling function andthe like for controlling a tuner section and the TV main body unit 103.Note that in the present embodiment, the TV main body unit 103 isexplained using a liquid crystal TV as an example of a thin displaydevice. For example, a system illustrated in FIG. 13 is conceivable.FIG. 13 is explained later.

As described above, in the wireless transmission network 1 formedbetween the wireless center unit 102 and the TV main body unit 103, datais transmitted/received by a SS wireless method. Here, as a frequencyband, the 2.4 GHz band is used. Note that recently the 5 GHz band isavailable as a frequency band, and the 5 GHz band may be used instead ofthe 2.4 GHz band.

Moving image data, DVD-Video data, or digital broadcasting data istransmitted from the wireless center unit 102 to the TV main body unit103, using an MPEG (Moving Picture Expert Group) 2 image compressionformat, through a communication line whose capacity is more than 10Mbps. Further, command (controlling signal) transmission between thewireless center unit 102 and the TV main body unit 103 is performedusing the SS wireless method.

Here, MPEG is explained.

When coded streams (bit rows) of MPEG video and MPEG audio, includingother coded streams, are applied to a practical application, it isnecessary to multiplex, synthesize, and combine the coded streams,including synchronization of the coded streams, and at the same time itis necessary to cause the streams to have a data form suitable for aformat or protocol inherent in storage media or a network.

There are two kinds of MPEG2 system: one is a program stream (MPEG2-PS),which constitutes a program as with MPEG1, and the other is a transportstream (MPEG2-TS) which can constitute a plurality of programs.

An MPEG stream is a byte stream in which units such as flags (there aremany 1 bit flags) and headers are ordered by 1 byte. All MPEG systemshave a common data structure in which information indicative of lengthis disposed ahead of a data portion whose length is not fixed, and whenthe data portion is unnecessary, the data portion is skipped or abeginning of the next data group is located, and thereby reliableseparated processing can be performed.

In order to prevent an over flow or under flow of image data and audiodata on a decoding-side, it is necessary for a device which receives acompressed image and audio signal, based on an MPEG coding method, tosynchronize image and audio sampling frequencies on a coding-side withimage and audio sampling frequencies or STC (System Time Clock) on thedecoding-side.

For that reason, a decoding device synchronizes the image and audiosampling frequencies on the coding-side with the image and audiosampling frequencies on the decoding-side by using PCR (Program ClockReference) or SCR (System Clock Reference) which are defined by MPEG2system standard (ISO/IEC standard 13818-1).

Here, the wireless center unit 102 and the TV main body unit 103 of thewireless AV system 101 having the above structure are fully explainedbelow with reference to FIGS. 2 and 3.

FIG. 2 is a block diagram illustrating an outline of the wireless centerunit 102 and FIG. 3 is a block diagram illustrating an outline of the TVmain body unit 103.

As illustrated in FIG. 2, the wireless center unit 102 is constituted ofa wireless center 2, and an SS transmission/reception unit 36 providedas communication means (communication section) for transmitting datafrom the wireless center 2 to the TV main body unit 103 (see FIG. 1)using the SS wireless method, and receiving a command (control command)from the TV main body unit 103.

The wireless center 2 includes: a BS tuner 31, connected with the BSterminal 11, for receiving and selecting BS broadcasting by a channelselection signal; a U/VHF tuner 32, connected with the U/VHF antennaterminal 12, for receiving and selecting U/VHF broadcasting by a channelselection signal; an image/audio demodulating section 33 fordemodulating an image/audio (AV) signal received and selected by the BStuner 31 or the U/VHF tuner 32; an audio switching section 34 forswitching, according to an audio switching signal, between a receivedaudio and information concerning TV programs such as EPG (ElectricalProgram Guide); a first AV selector 35 for selecting, using a sourceselection signal, (i) image/audio information received (ii) informationconcerning programs, and (iii) external input information from the video1 input terminal 14, the video 2 input terminal (decoder input) 15, andthe video 3 input terminal (which doubles as monitor/BS output) 16; awireless center microcomputer 37 for controlling each of the sections;an EEPROM (electrically erasable programmable ROM) 38 which is anelectrically rewritable non-volatile memory for storing a variety ofdata items such as a controlling program of the wireless centermicrocomputer 37, communication control data, and a communicationchannel changing program.

The wireless center microcomputer 37 transmits a channel selectionsignal 41 to the BS tuner 31 and the U/VHF tuner 32, transmits an audioswitching signal 42 to the audio switching section 34, transmits asource selection signal 43 to the first AV selector 35, and transmitsand receives a TV command 44 to and from the SS transmission/receptionunit 36.

Further, the wireless center microcomputer 37 also serves as: a controldata generating section for generating later-mentioned control data; adiscriminating section for discriminating a device to be controlledaccording to a discrimination code included in the control data; and acontrol data transmission section for transmitting the control data tothe discriminated controlled device.

The channel selection signal 41 includes information for specifying achannel of a TV program. Further, the audio switching signal 42 includesinformation for switching audios such as main audio, sub audio, stereo,monaural and the like. Further, the source selection signal 43 includesinformation for selecting from an audio/image signal from an externaldevice such as the video 1 input terminal 14 through the video 3 inputterminal 16, and an audio/image signal received by the BS tuner 31 andthe U/VHF tuner 32.

That is, the BS tuner 31 and the U/VHF tuner 32 accept broadcast of aprogram channel specified by the channel selection signal 41 from thewireless center microcomputer 37.

Further, the audio switching section 34 switches audios outputted fromthe image/audio demodulating section 33 to audios specified by the audioswitching signal 42 from the wireless center microcomputer 37.

Further, the first AV selector 35 selects a source (an image/audiosignal from an external device, such as via the video 1 input terminal14, and an image/audio signal from the BS tuner 31 or U/VHF tuner 32)specified by the source selection signal 43 from the wireless centermicrocomputer 37.

Further, the TV command 44 is a control signal transmitted/receivedbetween the wireless center microcomputer 37 and the SStransmission/reception unit 36, for controlling the whole of the device.

That is, the TV command 44 is generated in the wireless centermicrocomputer 37 and transmitted to the SS transmission/reception unit36, and further is transmitted to the TV main body unit 103 which is adevice with which the SS transmission/reception unit 36 communicates. Onthe other hand, in the wireless center unit 102, the wireless centermicrocomputer 37 receives a TV command 71 (see FIG. 3) from the TV mainbody unit 103 which communicates via the SS transmission/reception unit36.

As a result, in the TV main body unit 103, by receiving the TV command44 from the wireless center unit 102 with which the TV main body unit103 is in communication, each section of the TV main body unit 103 iscontrolled, and in the wireless center unit 102, by receiving the TVcommand 71 (see FIG. 3) from the TV main body unit 103 with which thewireless center unit 102 is in communication, each section of thewireless center unit 102 is controlled.

Note that in the present embodiment, the wireless center 2 having the BStuner 31 and the U/VHF tuner 32 as a broadcast tuner is exemplified.However, the wireless center 2 may be arranged so as to have a tuner forreceiving analog broadcasting, or a tuner for receiving digitalbroadcasting. Further, the tuner for receiving digital broadcasting maybe a tuner for satellite digital broadcasting, or a tuner forterrestrial digital broadcasting.

The SS transmission/reception unit 36 is constituted of: an A/Dconversion section 51 for converting data selected by the first AVselector 35 in the wireless center 2 into a digital signal; an MPEG2encoder 52 for converting data converted into a digital signal by theA/D conversion section 51 into an MPEG2 image compression format; an SSwireless transmission/reception engine 53 constituted of an SS wirelessdevice and wireless controlling section for transmitting transmissiondata (such as MPEG2 streams or commands) by the SS wireless method; anda first SS-CPU 54 for controlling each section of the SS transmissionunit and detecting a state of radio wave.

The SS wireless transmission/reception engine 53 has: a transmittingfunction for transmitting an MPEG2 stream such as image and/or audiodata or a command such as control data to an SS transmission/receptionunit 61 (mentioned later in relation to FIG. 3) of the TV main body unit103; and a receiving function for receiving a command such as controldata from the SS transmission/reception unit 61.

Note that in the present embodiment, a program for controlling thewireless center unit 102 is stored in the EEPROM 38 so as to berewritable. Therefore, by rewriting the program, control contents can beeasily changed. The reason for storing the program for controlling thewireless center unit 102 in a rewritable memory is to avoid wasting atime for changing a mask ROM with respect to each debug in systemdevelopment. Namely, by using a non-volatile memory (e.g. EPROM orEEPROM) as a program ROM, a time for developing or modifying a programis greatly reduced. Further, by downloading a program so as to rewriteprogram contents of the EEPROM 38, it becomes easy to upgrade or changethe function.

Next, the TV main body unit 103 is fully explained below with referenceto FIG. 3.

As illustrated in FIG. 3, the TV main body unit 103 is constituted of aTV main body 3, and an SS transmission/reception unit 61, which acts ascommunication means for transmitting a command from the TV main body 3to the wireless center unit 102 (see FIG. 1) using the SS wirelessmethod, and for receiving data from the wireless center unit 102.

The SS transmission/reception unit 61 transmits/receives TV commands 71and receives an MPEG stream or command transmission data transmittedfrom the SS transmission/reception unit 36 of the wireless center unit102, and decodes (restores) the received MPEG stream and the like intothe original data. The SS transmission/reception unit 61 is fullyexplained later.

The TV main body 3 is constituted of: a second AV selector 62 forselecting between data restored by the SS transmission/reception unit 61and an external AV signal inputted via the video 4 input terminal 21,which doubles as a TV output; a TV section 63 (a part of informingmeans) constituted of LCD or the like for displaying an image signal andoutputting an audio signal; a TV microcomputer 64 (a part of informingmeans) for controlling the whole of the device, bytransmitting/receiving TV commands 71 and transmitting a sourceselection signal 72, an OSD (On Screen Display) signal 73 and the like;an EEPROM 65 which is an electrically rewritable non-volatile memory forstoring a variety of data items such as a controlling program of the TVmicrocomputer 64, communication control data, and a communicationchannel changing program; a remote control light receiving section 66for receiving a control command in the form of light from a remotecontrol device (not shown); a battery 67; a battery chargermicrocomputer 68 for controlling charging/discharging of the battery 67;and an OSD synthesizing section 69 for synthesizing an image signaloutputted from the second AV selector 62 and the OSD signal 73 outputtedfrom the TV microcomputer 64 so as to output the synthesized signal tothe TV section 63.

The TV microcomputer 64 also serves as: a control data generatingsection for generating later-mentioned control data; a discriminationsection for discriminating a controlled device according to adiscrimination code included in the control data; and a control datatransmission section for transmitting the control data to thediscriminated controlled device.

The SS transmission/reception unit 61 is constituted of: an SS wirelesstransmission/reception engine 81 constituted of an SS wireless deviceand wireless control section for receiving data transmitted using the SSwireless method; an MPEG2 decoder 82 for decoding a received MPEG2stream; a D/A conversion section 83 for converting decoded data into ananalog signal; and a second SS-CPU 84 (communication state detectionmeans) for controlling each section of the SS transmission/receptionunit and detecting a state of an radio wave.

The SS wireless transmission/reception engine 81 has: a receivingfunction for receiving an MPEG2 stream, a command or the like from theSS transmission/reception unit 36 of the wireless center unit 102; and atransmitting function for transmitting a command or the like from the SStransmission/reception unit 61.

Particularly, the second SS-CPU 84 has a function of radio wave statedetection means for detecting a communication state (such as strength ofan radio wave or hindrance to a communication route) between thewireless center unit 102 and the TV main body unit 103, according to anelectric field strength of a received radio wave and a request forre-transmission based on an error ratio. Information indicating a stateof the detected radio wave is transmitted to the TV microcomputer 64 asa TV command 71.

In the present embodiment, an arrangement is described in which thesecond SS-CPU 84 in the SS transmission/reception unit 61 of the TV mainbody unit 103 has the function of detecting the state of the radio wave.However, it may be that the first SS-CPU 54 in the SStransmission/reception unit 36 of the wireless center unit 102 has thesame function and information indicating a state of a detected radiowave is transmitted as a command from the wireless center unit 102 tothe TV main body unit 103. Alternatively, it may be that both the firstSS-CPU 54 and the second SS-CPU 84 have the function of detecting thestate of the radio wave. Further, it may be that the TV microcomputer 64or the wireless center microcomputer 37 has the function of detectingthe state of the radio wave.

The TV microcomputer 64 controls the whole of the device, and has afunction of informing means for informing, based on a detectedcommunication state, a variety of messages such as discontinuation ofimage/audio data, changing of a communication channel, connecting of acommunication channel, and reception quality information including beingoutside of communication range.

Further, the TV microcomputer 64 performs communication channel changingcontrol in which how long a communication is discontinued is measured,and the communication channel is maintained until a predetermined timepasses from a time when the communication is discontinued.

Further, the TV microcomputer 64 includes an OSD generating functionsection, and displays information such as a program channel, time, orvolume, on a screen such as a TV. It is general that an image devicesuch as a TV and an electronic apparatus such as a TV conference systemdisplay information such as a program channel, time, or volume on a TVscreen. OSD data is maintained not in the form of an image but in a formreferred to as a bit map. The OSD data in the bit map form is convertedinto pixel values in YUV form, which represents colors by Y, Cb, and Cr,and the converted pixels are superposed on an original image of a TVbroadcast or the like. The superposing is performed in the OSDsynthesizing section 69.

Further, by connecting an image reproducing device (not shown) such aDVD to the video 4 input terminal 21, which doubles as a TV output, itis possible to superpose an OSD display on a reproduced image on adisplay screen.

Further, the TV main body 3 may be arranged so as to include a speaker,a key input section, a slot and the like (these are not shown). The slotis for inserting a card-type external extension storage medium, anddirectly reading data by attaching a card type external extensionstorage medium to the slot. Examples of the card type external extensionstorage medium are: an SRAM (Static RAM) card which maintains writteninformation by power source back up; a Compact Flash (CF)™ made of aflash memory and the like which does not need power source back up; asmart media; a memory stick; and a micro hard disc drive (HDD), whosesize is substantially the same as a Compact Flash, or which may beattached to a PC card Type II.

Further, the remote control light receiving section 66 included in theTV main body 3 is a light communication port section using IR (InfraredRays), and receives a light signal from a remote control device forcontrolling a variety of operations in the TV main body unit 103 or thewireless center unit 102. To be specific, the remote control lightreceiving section 66 is an I/O port for performing light communicationbased on IrDA (Infrared Data Association), ASK and the like, which arestandards used for transmission of data by infrared rays, or a wirelesscommunication port performing communication by an radio wave.

Further, the battery 67 supplies a predetermined power to each sectionof the TV main body unit 103. When it is possible to charge the battery67, the battery charger microcomputer 68 detects that, for example, theTV main body unit 103 is attached to the wireless center unit 102 orother cradle, and controls charging/discharging of a charge medium (notshown) of the battery 67 via a power supply terminal (not shown). To bespecific, the battery charger microcomputer 68 stores and counts adischarged current from a battery pack, and begins charging when itjudges that a remaining amount of charge in the battery pack is lessthan a predetermined value. In charging, the battery chargermicrocomputer 68 stores and counts a current charged to the batterypack, and stops charging when it judges that the battery pack is fullycharged. When the TV main body 3 is separated from a commercial powersource, the charged battery 67 serves as a main power source for aportable TV, and supplies power to each section of the TV main body 3.

Next, a method is explained for transmitting/receiving control databetween the wireless center 2 and the TV main body 3 in the wireless AVsystem 101 having the above arrangement of the present embodiment.

Here, according to an input by a user, or to an action by apredetermined program, the wireless center microcomputer 37 of thewireless center unit 102 transmits control data including adiscrimination code and a control command to the SStransmission/reception unit 36, the SS transmission/reception unit 61 ofthe TV main body unit 103, or the TV microcomputer 64 of the TV mainbody 3.

Here, the discrimination code is a code for discriminating which of aplurality of controlled devices the control command is for, and isgenerally added to a header part of control data.

The TV command 44 transmitted by the wireless center microcomputer 37 ofthe wireless center 2 is received by the first SS-CPU 54 of the SStransmission/reception unit 36. When the TV command 44 is control dataincluding a control command for the SS transmission/reception unit 36,the first SS-CPU 54 performs a corresponding process.

When the TV command 44 transmitted by the wireless center microcomputer37 is control data for the SS transmission/reception unit 61 or TVmicrocomputer 64 of the TV main body unit 103, the first SS-CPU 54 ofthe SS transmission/reception unit 36 performs a predetermined coding ofthe data, and then transmits by wireless the coded data via the SSwireless transmission/reception engine 53.

The SS transmission/reception unit 61 of the TV main body unit 103receives the wireless data and discriminates control data by the secondSS-CPU 84, and when the control data is for the SStransmission/reception unit 61, the second SS-CPU 84 performs apredetermined process.

When the received data is control data for the TV microcomputer 64, thesecond SS-CPU 84 transmits the control data as the TV command 71 to theTV microcomputer 64. As a result, the TV microcomputer 64 performs apredetermined process in the TV main body 3.

FIGS. 4( a) through 4 (c) schematically illustratetransmission/reception of control data (referred to as a control commandhereinafter) between the wireless center unit 102 and the TV main bodyunit 103.

Note that in FIGS. 4( a) through 4(c), a controlling device means thewireless center microcomputer 37 of the wireless center unit 102, awireless station 1 means the SS transmission/reception unit 36 of thewireless center unit 102, a wireless station 2 means the SStransmission/reception unit 61 of the TV main body unit 103, and acontrolled device means the TV microcomputer 64 of the TV main body unit103.

FIG. 4( a) illustrates a case where the controlling device transmitscontrol data having a control command directed to the wireless station 1(own station) in the controlling device itself. This case is referred toas a first control data transmission/reception mode. In the firstcontrol data transmission/reception mode, it is conceivable that, forexample, the wireless center microcomputer 37 transmits control datahaving a control command for changing an MPEG transmission rate orswitching a wireless channel, to the SS transmission/reception unit 36,according to a wireless communication circumstance.

FIG. 4( b) illustrates a case where the controlling device transmitscontrol data including a control command to the wireless station 2(other station), which is different to the controlling device. This caseis referred to as a second control data transmission/reception mode. Inthe second control data transmission/reception mode, it is conceivablethat, for example, the wireless center microcomputer 37 transmitscontrol data including a control command for changing the MPEGtransmission rate or switching the wireless channel, to the SStransmission/reception unit 61 of the TV main body unit 103, accordingto a wireless communication circumstance.

FIG. 4( c) illustrates a case where the controlling device transmitscontrol data including a control command to a controlled device, whichis different to the controlling device. This case is referred to as athird control data transmission/reception mode. In the third controldata transmission/reception mode, it is conceivable that, for example,the wireless center microcomputer 37 transmits control data including acontrol command for changing an inputted channel of a program orchanging a variety of settings.

Further, opposite to the cases illustrated in FIGS. 4( a) through 4(c),in an example where the TV microcomputer 64 of the TV main body unit 103is a controlling device and the wireless center microcomputer 37 of thewireless center unit 102 is a controlled device, it is conceivable thata control command for changing a tuner channel or audio setting istransmitted. This example is fully explained later.

Next, a data structure of control data transmitted/received in thepresent embodiment is explained. The wireless AV system 101 of thepresent embodiment makes it easy to discriminate control data, bytransmitting/receiving the control data with a predetermined key code ina header part (control command) of the control data.

FIG. 5 illustrates an example of a key code included in control data. Inthe example illustrated in FIG. 5, a key code for discriminating controldata is “0xFF”. The key code is preset, and can be set arbitrarily.Further, when a code identical with the preset key code “0xFF” isincluded in a main body of the data, this code is converted according toa predetermined rule. Specifically, “0xFE” in the main body of the datais converted into “0xFE 0x00”, and “0xFF” is converted into “0xFE 0x01”.

With such a conversion, control data transmitted/received in the presentsystem is easily discriminated with use of the key code “0xFF” includedin the header.

Further, by converting “0xFE 0x00” into “0xFE” and “0xFE 0x01” into“0xFF” at a receiving-side of the control data, it is possible to easilyrestore the original control data.

FIG. 6 illustrates an example of a format of control datatransmitted/received in the wireless AV system 101 of the presentembodiment. As illustrated in FIG. 6, control data is constituted of acommand discrimination ID (a control command including a key code), adata size, a main body of data (control command), and a checksum.

The command discrimination ID is predetermined as an ID fordiscriminating the destination to which the command is transmitted. Inthe present embodiment, a command for the wireless station (own station)is discriminated by ID=1, a command for the wireless station (otherstation) is discriminated by ID=2, and a command for a controlled devicesent via the other station is discriminated by ID=3. Further, a commandfor an external device connected to the controlled device isdiscriminated by ID=4.

The checksum is a value (low 1 byte) calculated by adding values of acommand discrimination ID, a data size, and a main body of data, using 1byte as a unit.

FIGS. 7( a) through 7(d) illustrate examples of code conversions ofcontrol commands.

FIG. 7( a) illustrates an example of a conversion of the control commandfor the wireless station (own station) (control command for the wirelessstation 1). The command discrimination ID in this case is set to 1.

FIG. 7( b) illustrates an example of a conversion of the control commandfor the wireless station (other station) (control command for thewireless station 2). The command discrimination ID in this case is setto 2.

FIG. 7( c) illustrates an example of a conversion of the control commandfor the controlled device sent via the other station. The commanddiscrimination ID in this case is set to 3.

FIG. 7( d) illustrates an example of a conversion of the control commandfor the external device connected to the controlled device. The commanddiscrimination ID in this case is set to 4.

In the case of any command, the data after conversion includes a keycode “0xFF” in the head of the data, and “0xFE” and “0xFF” in the databefore conversion are converted into “0xFE 0x00” and “0xFE 0x01”respectively, so that the key code is not misidentified.

Here, concrete examples of a variety of control commands are describedbelow.

Examples of n own station commands (command discrimination ID=1) are,

Reception quality acquisition command: 0x01 0x00 0x01 0x01 0x03

Channel number acquisition command: 0x01 0x00 0x01 0x02 0x04

Examples of other-station commands (command discrimination ID=2) are,

Channel changing command: 0x02 0x0 00x01 0x01 0x04

Name of other-station device acquisition command: 0x02 0x00 0x01 0x020x05

Examples of commands for a device connected to the other-station(command discrimination ID=3) are,

Reproduction command: 0x03 0x00 0x02 0x00 0x01 0x06

Stop command: 0x03 0x00 0x02 0x00 0x02 0x07

Fast forward command: 0x03 0x00 0x02 0x00 0x03 0x08

Rewinding command: 0x03 0x00 0x02 0x00 0x04

In the examples illustrated in FIGS. 4( a) through 4(c), the controllingdevice is the wireless center microcomputer 37 of the wireless centerunit 102, and the controlled device is the TV microcomputer 64 of the TVmain body unit 103. On the other hand, it may be that the controllingdevice is the TV main body unit 103 and the controlled device is thewireless center unit 102. An example of this case is explained below,with respect to each purpose of each control command, with reference toFIGS. 8( a) and 8(b) through FIGS. 11( a) and (b).

Here, it is assumed that the controlling device is the TV microcomputer64 of the TV main body unit 103, and that the wireless station 1 is theSS transmission/reception unit 61 of the TV main body unit 103. Further,it is assumed that the wireless station 2 is the SStransmission/reception unit 36 of the wireless center unit 102, and thatthe controlled device is the wireless center microcomputer 37 of thewireless center unit 102. It is assumed that the external device is anAV device (not shown) connected to the wireless center unit 102, such asa DVD recorder.

When acquisition of transmitted radio wave strength in the wirelessstation 1 is intended, the controlling device transmits control data tothe wireless station 1, as illustrated in FIG. 8( a). In this case, thecommand discrimination ID=1, and the control data has a data structureillustrated in FIG. 8( b). Here, as illustrated in FIG. 7( a), thecontrol command included in the control data is converted by the TVmicrocomputer 64, acting as the controlling device, of the TV main bodyunit 103.

Note that the control data illustrated in FIG. 8( b) includes a 1 bytecontrol command (a control command after conversion, illustrated in FIG.7( a)) corresponding to the command discrimination ID=1, 2 bytes of sizedata for indicating a size of a main body of the control data, 1 byte ofdata showing a main body of the data (a command number indicatingacquisition of transmitted radio wave strength), and 1 byte of data(CRC) indicating a checksum.

When acquisition of received radio wave strength in the wireless station1 is intended, the controlling device transmits a control command to thewireless station 2 via the wireless station 1. In this case, the commanddiscrimination ID=2, and the control data has a data structureillustrated in FIG. 9( b). Here, as illustrated in FIG. 7( b), thecontrol command included in the control data is converted by the TVmicrocomputer 64, acting as the controlling device, of the TV main bodyunit 103.

Note that the control data illustrated in FIG. 9( b) includes a 1 bytecontrol command (a control command after conversion, illustrated in FIG.7( b)) corresponding to the command discrimination ID, 2 bytes of sizedata for indicating a size of the control data, 1 byte of dataindicating a main body of the data (a command number indicatingacquisition of a received radio wave strength), and 1 byte of data (CRC)indicating a checksum.

When switching of an external input in the controlled device isintended, the controlling device transmits a control command to thecontrolled device via the wireless stations 1 and 2, as illustrated inFIG. 10( a). In this case, the command discrimination ID=3, and thecontrol data has a data structure illustrated in FIG. 10( b). Here, asillustrated in FIG. 7( c), the control command included in the controldata is converted by the TV microcomputer 64, acting as the controllingdevice, of the TV main body unit 103.

Note that the control data illustrated in FIG. 10( b) includes 1 byte ofdata corresponding to the command discrimination ID, 2 bytes of sizedata indicating a size of the control data, 1 byte of data indicating amain body of the data (a command number corresponding to inputswitching), data corresponding to a parameter indicating an externalinput 1, 1 byte of data (CRC) indicating a checksum.

When direct remote control of an external device via the controlleddevice is intended, the controlling device transmits a control commandto the external device via the wireless stations 1 and 2 and thecontrolled device. In this case, the command discrimination ID=4, andthe control data has a data structure illustrated in FIG. 11( b). Here,as illustrated in FIG. 7( d), the control command included in thecontrol data is converted by the TV microcomputer 64, acting as thecontrolling device, of the TV main body unit 103.

Note that the control data illustrated in FIG. 11( b) includes 1 byte ofdata corresponding to the command discrimination ID, 2 bytes of dataindicating a size of the control data (here, a main body of the data is80 bytes), data indicating a main body of the data (a command numbercorresponding to a remote-control-issued function), data correspondingto a parameter indicating an IrDA sampling data message, and 1 byte ofdata (CRC) indicating a checksum.

As a concrete example of control command transmission, as illustrated inFIGS. 11( a) and 11(b), for example, the wireless AV system 101illustrated in FIG. 12 is considered. Here, in the wireless AV system101 illustrated in FIG. 12, it is possible to operate, using the remotecontroller 130, an external device such as a DVD player or a video deckconnected to the wireless center unit 102, via the TV main body unit103.

As an application of such a remote control operation, a systemillustrated in FIG. 13 is conceivable. In FIG. 13, three TV main bodyunits 103 a through 103 c transmit control data to one wireless centerunit 102, and perform remote control of external devices (devices Athrough C) connected to the wireless center unit 102. Namely, thewireless center unit 102 transmits control data received from the TVmain body unit 103 to remote control light receiving sections (110 athrough 110 c) of the remotely controlled devices.

In this case, the control data is generated on the TV main body unit 103side, transmitted from the TV main body unit 103 to the wireless centerunit 102, and transmitted from the wireless center unit 102 to each ofthe external devices. A process for distributing the control data to theexternal devices is performed in the wireless center microcomputer 37 ofthe wireless center unit 102.

The wireless AV system 101 to which the wireless control system of thepresent invention is applied is explained above, with reference toconcrete embodiments. However, the present invention is not limited tothe embodiments. It is possible for a person with ordinary skill in theart to which the invention pertains, to perform a variety of changes ormodifications to arrangements and functions of the invention accordingto each of the embodiments or other embodiments, within the scope of thepresent invention.

For example, in the present embodiment, as a wireless AV device, aportable TV is exemplified. However, the present invention is notlimited to a TV receiver, and is applicable to a device having awireless communication function or to a device into which a wirelesscommunication function is merged. For example, the AV device may be aVTR (Video Tape Recorder), or record reproducing device which stores arecord in a HDD or DVD. Further, a device for transmission/reception ofdata may be a device in which a function for transmission/reception ofdata is merged with an information device function represented by apersonal computer, and applicable to all the systems. Further, contentsof transmitted/received data may be anything.

Further, in the present embodiment, the TV receiver is exemplified, butthe present invention is not limited to this, and is applicable to apersonal computer with a tuner, or to other AV devices using a tuner.

Further, kinds of each section constituting the wireless communicationdevice and the wireless AV system, and kinds/styles of settinginformation or the like are not limited to the embodiments.Particularly, the present invention may be preferably applied to adevice based on HAVi.

Further, as a tuner, two broadcasting tuners such as a BS tuner and aU/V tuner are exemplified, but kinds and numbers of broadcasting tunersare not limited to this. For example, a CS tuner may be used.

Further, in the present embodiment, names such as a wirelesscommunication device and a wireless AV system are used, but these namesare used for convenience of explanation, and they may be a wirelesscommunication apparatus, an AV device, a broadcasting selecting device,or the like.

The wireless communication device and the wireless AV system asdescribed above can be realized by a program for causing the wirelesscommunication device and the wireless AV system to function. The programmay be stored in a storage medium readable by a computer. In the presentinvention, the storage medium may be program media being a main memoryitself, or program media readable by inserting a storage medium into aprogram reading device provided as an external storage device.

In either case, the stored program may be arranged so as to be carriedout by access by a CPU. Alternatively, in either case, the program maybe arranged so as to be read out, downloaded to a program storage area(not shown) and carried out. A program for downloading is stored in amain body of the device beforehand.

Here, the program media may be arranged so as to be a storage mediumdetachable from the main body, and be a medium permanently storing aprogram. For example, tapes such as a magnetic tape and a cassette tape,discs such as a magnetic disc (e.g. Floppy™ disc or a hard disc) or anoptical disc (e.g. CD-ROM, MO, MD, or DVD), cards such as an IC card oran optical card, and semiconductor memories such as a mask ROM, EPROM,EEPROM, or flash ROM.

Further, when means (not shown) for connecting with an externalcommunication network is provided, the program media may be arranged soas to be a medium for temporarily storing a program so as to downloadthe program from a communication network via means for connecting withan external communication network.

Note that when a program is downloaded from the communication network inthis way, a program for downloading may be stored in the main body ofthe device beforehand, or may be installed from other storage media.Contents to be stored in the storage media are not limited to programs,and may be data.

Further, at present, new terrestrial digital broadcasting has beenprepared, which will take the place of analog terrestrial broadcastingviewed across the country. The terrestrial digital broadcasting startedin 2003 in three urban areas: Kanto, Kinki, and Tokai, and will spreadacross the country in 2006. Along with this spreading, current analogbroadcasting will be abolished in 2011.

ISDB (Integrated Services Digital Broadcasting) is a concept of the nextgeneration of integrated digital broadcasting that treats allinformation such as images, audio, and data items, as digital dataitems. As a concrete service of ISDB, digital TV broadcasting, digitalaudio broadcasting, facsimile broadcasting, multimedia broadcasting andthe like are studied. As a transmission channel for ISDB, a satellitebroadcast wave, a terrestrial broadcast wave, and a wired transmissionchannel such as a co-axial cable or an optical fiber are now considered.

Technical standard ISDB-T (Terrestrial) of the terrestrial digitalbroadcasting adopts OFDM (Orthogonal Frequency Division Multiplexing)that uses a number of carriers as a modulation method, and therebyallows reduction of ghosting caused by a plurality of transmissionroutes (multiple-paths) such as reflection from buildings. Further,ISDB-T defines a plurality of transmission modes, which define a carrierinterval, a plurality of modulation methods with respect to eachcarrier, and a plurality of guard intervals in temporal axis directionsprovided with respect to each effective symbol length, and accordingly alarge number of signal methods are allowed as standard. In practice, outof these methods, an optimal method is selected according to a service,such as fixed reception or mobile reception.

Further, in ISDB-T, one transmission channel (band is approximately 5.6MHz) is divided into 13 segments (1 segment=approximately 430 kHz), andthe modulation method is changed using this segment as a unit. As aresult, a broadcasting station can determine a signal arrangementarbitrarily, such as audio broadcasting and high definition broadcastingin one channel, and standard fixed broadcasting and mobile broadcastingin another channel.

Further, ISDB-T adopts an interleave in a temporal direction, and aradio wave used for ISDB-T is suitable for transmission to a movablebody. As such, ISDB-T allows stabilized reception even by a receivingdevice on a movable body, such as an in-vehicle TV, and a portableterminal such as a PDA (Personal Digital Assistant) or a mobile phone.In future, a service assuming such mobile reception is greatly expected.

Therefore, the wireless control system of the present invention can bepreferably used for such services.

Further, the present invention may be arranged as follows.

The device according to the present invention may be arranged to be adevice for transmitting/receiving control data among AV devicesconstituting the wireless AV system, including: means for generatingcontrol data; means for converting the generated control data; means fortransmitting/receiving by wireless the converted control data; and meansfor discriminating the converted control data and acquiring the databefore conversion.

Further, the means for converting the control data may be arranged sothat the means adds a key code for discriminating the control data to ahead part of the control data, and when data whose content is identicalwith the key code exists in another part of the control data, the meansperforms a predetermined conversion of the data.

Further, the control data may include: data by which the AV deviceconstituting the wireless AV system controls a wireless communicationstation in the AV device itself; data by which the AV device controls awireless communication station in an AV device other than the AV deviceitself; and data by which the AV device controls the AV device otherthan the AV device itself.

Further, the control data may include a command for changing a datatransmission rate, changing a wireless communication channel, changing atuner channel, and switching an input.

As described above, with the wireless AV system of the presentinvention, when transmission/reception of control data among the AVdevices is performed, it is possible to discriminate control dataaccording to a key code added to a header, without processing a mainbody of the data. As a result, it is possible to reduce the burden ofdata discrimination in a wireless station and a terminal.

The present invention is not limited to the embodiments, and a varietyof modifications are possible within the scope of the following claims.That is, embodiments obtained by combining technical means suitablymodified within the scope of the following claims are also within thetechnical scope of the present invention.

Each section of the wireless AV system 101 of the embodiments can berealized in such a manner that calculation means such as a CPU performsa program stored in storage means such as a ROM (Read Only Memory) orRAM, and controls input means such as a keyboard, output means such as adisplay, or communication means such as an interface circuit. Therefore,a computer having such means reads a storage medium for storing theprogram and carries out the program, and thereby a variety of functionsand a variety of processes of the wireless AV system 101 of the presentembodiment can be realized. Further, by storing the program in aremovable storage medium, it is possible to realize a variety of thefunctions and a variety of the processes in an arbitrary computer.

The storage medium may be program media being a memory (not shown), suchas a ROM, so as to be processed by a microcomputer, or program mediareadable by inserting a storage medium to a program reading device (notshown) provided as an external storage device.

In either case, it is preferable that the stored program is carried outby an access by a microprocessor. Further, it is preferable that theprogram is read out, downloaded to a program storage area of themicrocomputer and carried out. A program for downloading is stored inthe main body of the device beforehand.

Further, the program medium is a storage medium detachable from the mainbody, and permanently storing a program. For example, tapes such as amagnetic tape and a cassette tape, discs such as a magnetic disc (e.g. aflexible disc or a hard disc) or an optical disc (e.g. CD, MO, MD, orDVD), cards such as an IC card (including a memory card), andsemiconductor memories such as a masked ROM, EPROM (ErasableProgrammable Read Only Memory), EEPROM (Electrically ErasableProgrammable Read Only Memory), or flash ROM.

Further, when it is possible to connect the system with a communicationnetwork including the Internet, it is preferable that the program mediais a medium for temporarily storing a program so as to download theprogram from the communication network.

Further, when a program is downloaded from the communication network inthis way, it is preferable that a program for downloading is stored inthe main body of the device beforehand, or installed from other storagemedia.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

INDUSTRIAL APPLICABILITY

The wireless system of the present invention is preferably used for ahome AV network system (e.g. a wireless TV receiver having a separabledisplay) that transmits image and/or audio data by wireless. However,the wireless system of the present invention is not limited to this, andis widely applicable for a wireless communication device such as amobile phone/PHS (Personal Handy-Phone System)™ or a portableinformation terminal (PDA (Personal Digital Assistant)).

1. A wireless control system comprising a controlling device andcontrolled devices that are wirelessly controlled by the controllingdevice, wherein the controlling device wirelessly generates andtransmits control data to the controlled devices, the control dataincluding (i) a control command and (ii) a discrimination code fordiscriminating which of the controlled devices in the system the controlcommand is for, and the controlled devices receive the wirelesslytransmitted control data from the controlling device, read out thediscrimination code included in the control data, and discriminatingwhich of the a controlled device in the system the control command isfor, the control data being transmitted to a controlled devicediscriminated by the discrimination section, wherein the control commandincludes one of a first command, a second command, and a third command,the first command includes a reception quality acquisition command and achannel number acquisition command, the second command includes achannel changing command and a name of other-station device acquisitioncommand, and the third command includes a reproduction command, a stopcommand, a fast forward command, and a rewinding command, wherein thefirst command is control data transmitted to a first controlled deviceby the controlling device; the second command is control datatransmitted to a second controlled device by the controlling device viathe first controlled device; and the third command is control datatransmitted to a third controlled device by the controlling device viathe first controlled device and via the second controlled device.
 2. Awireless control system comprising a controlling device and controlleddevices that are wirelessly controlled by the controlling device,wherein the controlling device includes: a control data generatingsection for generating control data including (i) a control command and(ii) a discrimination code for discriminating which of the controlleddevices in the system the control command is for; and a wirelesscommunication section for transmitting the control data transmitted fromthe control data generating section, to a controlled device with whichthe wireless communication section is in communication, and wherein eachof the controlled devices includes: a wireless communication section forreceiving the control data from the controlling device; a discriminationsection for reading out the discrimination code included in the receivedcontrol data, and discriminating which of the controlled devices thecontrol command included in the control data is for; and a control datatransmission section for transmitting the control data to a controlleddevice discriminated by the discrimination section, wherein, whengenerated control data includes same data as a predetermined key code,the control data generating section performs a predetermined conversionof the same data, and transmits the converted control data to thewireless communication section.
 3. The wireless control system as setforth in claim 2, wherein control data generated in the control datagenerating section is any one of control data to be transmitted to acontrol section included in the controlling device, control data to betransmitted to the wireless communication section in the controllingdevice, control data to be transmitted to a control section included inthe controlled devices, and control data to be transmitted to thewireless communication section in the controlled devices.
 4. Thewireless control system as set forth in claim 2, wherein the wirelesscommunication section transmits control data using a spread spectrumwireless system.
 5. The wireless control system as set forth in claim 2,wherein the wireless communication section performs low power, closerange, two-way wireless communication such as a wireless LAN, Bluetoothor UWB (Ultra Wide Band).
 6. The wireless control system according toclaim 2, wherein, when the predetermined key code for discriminating thecontrol data is provided in header of the control data, and data body ofthe control data includes same data as the predetermined key code, thecontrolling devices performs a predetermined conversion of the samedata, and transmits the converted control data to the controlleddevices.
 7. A wireless control system comprising a controlling deviceand controlled devices that are wirelessly controlled by the controllingdevice, wherein the controlling device includes: a control datagenerating section for generating control data including (i) a controlcommand and (ii) a discrimination code for discriminating which of thecontrolled devices in the system the control command is for; and awireless communication section for transmitting the control datatransmitted from the control data generating section, to a controlleddevice with which the wireless communication section is incommunication, and wherein each of the controlled devices includes: awireless communication section for receiving the control data from thecontrolling device; a discrimination section for reading out thediscrimination code included in the received control data, anddiscriminating which of the controlled devices the control commandincluded in the control data is for; and a control data transmissionsection for transmitting the control data to a controlled devicediscriminated by the discrimination section, wherein the control dataincludes, as a control command, a command for performing a change of adata transmission rate, a change of a wireless communication channel, achange of a tuner channel, switching of an input, and acquisition of acommunication state, and wherein, when generated control data includessame data as a predetermined key code, the control data generatingsection performs a predetermined conversion of the same data, andtransmits the converted control data to the wireless communicationsection.
 8. Controlled devices, included in a wireless control systemcomprising a controlling device and controlled devices that arewirelessly controlled by the controlling device, said controlled devices(i) receiving control data which includes a discrimination code fordiscriminating between the controlled devices in the system, and (ii)discriminating a controlled device to carry out a control commandincluded in the control data, based on the discrimination code includedin the received control data, wherein the control command includes oneof a first command, a second command, and a third command, the firstcommand includes a reception quality acquisition command and a channelnumber acquisition command, the second command includes a channelchanging command and a name of other-station device acquisition command,and the third command includes a reproduction command, a stop command, afast forward command, and a rewinding command, wherein the first commandis control data transmitted to a first controlled device by thecontrolling device; the second command is control data transmitted to asecond controlled device by the controlling device via the firstcontrolled device; and the third command is control data transmitted toa third controlled device by the controlling device via the firstcontrolled device and via the second controlled device.
 9. The wirelesscontrol system according to claim 8, wherein, when a predetermined keycode for discriminating the control data is provided in header of thecontrol data, and data body of the control data includes same data asthe predetermined key code, the controlling devices performs apredetermined conversion of the same data, and transmits the convertedcontrol data to the controlled devices.
 10. Controlled devices, includedin a wireless control system comprising a controlling device andcontrolled devices that are wirelessly controlled by the controllingdevice, said controlled devices including: a wireless communicationsection for receiving from the controlling device control data includinga discrimination code for discriminating between the controlled devicesin the system; a discrimination section for reading out thediscrimination code included in the received control data anddiscriminating a controlled device to carry out a control commandincluded in the control data; and a control data transmission sectionfor transmitting the control data to the controlled device discriminatedby the discrimination section, wherein the control data includes, as acontrol command, a command for performing a change of a datatransmission rate, a change of a wireless communication channel, achange of a tuner channel, switching of an input, and acquisition of acommunication state, and wherein, when the control data includes samedata as a predetermined key code, the control data generating sectionperforms a predetermined conversion of the same data, and transmits theconverted control data to the wireless communication section.
 11. Acontrolling device, included in a wireless control system comprising acontrolling device and controlled devices that are wirelessly controlledby the controlling device, said controlling device wirelesslytransmitting control data to the controlled devices, the control datahaving, in a control command for controlling the controlled devices, adiscrimination code for discriminating between a controlled device towhich the control command is to be transmitted and other one or morecontrolled devices in the system, wherein the control data includes, asa control command, a command for performing a change of a datatransmission rate, a change of a wireless communication channel, achange of a tuner channel, switching of an input, and acquisition of acommunication state, and wherein, when the control data includes samedata as a predetermined key code, the control data generating sectionperforms a predetermined conversion of the same data, and transmits theconverted control data to the wireless communication section.
 12. Acontrolling device, included in a wireless control system comprising acontrolling device and controlled devices that are wirelessly controlledby the controlling device, said controlling device including: a controldata generating section for generating control data having, in a controlcommand for controlling the controlled devices, a discrimination codefor discriminating between a controlled device to which the controlcommand is to be transmitted and other one or more controlled devices inthe system; and a wireless communication section for transmitting thecontrol data transmitted from the control data generating section, to acontrolled device with which the wireless communication section is incommunication, wherein, when generated control data includes same dataas a predetermined key code, the control data generating sectionperforms a predetermined conversion of the same data, and transmits theconverted control data to the wireless communication section.
 13. Thewireless control system according to claim 12, wherein, when thepredetermined key code for discriminating the control data is providedin header of the control data, and data body of the control dataincludes same data as the predetermined key code, the controllingdevices performs a predetermined conversion of the same data, andtransmits the converted control data to the controlled devices.
 14. Amethod of controlling devices, in which a controlling device wirelesslycontrols controlled devices, wherein the controlling device wirelesslytransmits control data to the controlled devices, the control datahaving, in a control command for controlling the controlled devices, adiscrimination code for discriminating between a controlled device towhich the control command is to be transmitted and other one or morecontrolled devices in the system, and the controlled devices receive thecontrol data wirelessly transmitted from the controlling device, and,based on the discrimination code included in the received control data,discriminate a controlled device to carry out the control commandincluded in the control data, and transmit the control data to thediscriminated controlled device, wherein the control data includes, as acontrol command, a command for performing a change of a datatransmission rate, a change of a wireless communication channel, achange of a tuner channel, switching of an input, and acquisition of acommunication state, and wherein, when the control data includes samedata as a predetermined key code, the control data generating sectionperforms a predetermined conversion of the same data, and transmits theconverted control data to the wireless communication section.
 15. Themethod of controlling devices according to claim 14, wherein, when thepredetermined key code for discriminating the control data is providedin header of the control data, and data body of the control dataincludes same data as the predetermined key code, the controllingdevices performs a predetermined conversion of the same data, andtransmits the converted control data to the controlled devices.
 16. Amachine-readable medium having instructions stored thereon, saidinstructions are read and executed by a processor for causing theprocessor to perform a method of discriminating between controlleddevices, comprising: receiving control data which includes adiscrimination code for discriminating between controlled devices in asystem, and (ii) discriminating a controlled device to carry out acontrol command included in the control data, based on thediscrimination code included in the received control data, wherein thecontrol command includes one of a first command, a second command, and athird command, the first command includes a reception qualityacquisition command and a channel number acquisition command, the secondcommand includes a channel changing command and a name of other-stationdevice acquisition command, and the third command includes areproduction command, a stop command, a fast forward command, and arewinding command, wherein the first command is control data transmittedto a first controlled device by the controlling device; the secondcommand is control data transmitted to a second controlled device by thecontrolling device via the first controlled device; and the thirdcommand is control data transmitted to a third controlled device by thecontrolling device via the first controlled device and via the secondcontrolled device.
 17. A machine-readable medium having instructionsstored thereon, said instructions are read and executed by a processorfor causing the processor to perform a method of discriminating betweencontrolled devices, comprising: receiving control data including adiscrimination code for discriminating between controlled devices in asystem; reading out the discrimination code included in the receivedcontrol data and discriminating a controlled device to carry out acontrol command included in the control data; and transmitting thecontrol data to the controlled device discriminated, wherein the controldata includes, as a control command, a command for performing a changeof a data transmission rate, a change of a wireless communicationchannel, a change of a tuner channel, switching of an input, andacquisition of a communication state, and wherein, when the control dataincludes same data as a predetermined key code, a predeterminedconversion of the same data is preformed, and the converted control datais transmitted.
 18. A machine-readable medium having instructions storedthereon, said instructions are read and executed by a processor forcausing the processor to perform a method of discriminating betweencontrolled devices, comprising: transmitting control data to controlleddevices, the control data having, in a control command for controlling acontrolled devices, a discrimination code for discriminating between thecontrolled device to which the control command is to be transmitted andother one or more controlled devices in a system, wherein the controldata includes, as a control command, a command for performing a changeof a data transmission rate, a change of a wireless communicationchannel, a change of a tuner channel, switching of an input, andacquisition of a communication state, and wherein, when the control dataincludes same data as a predetermined key code, a predeterminedconversion of the same data is preformed, and the converted control datais transmitted.
 19. A machine-readable medium having instructions storedthereon, said instructions are read and executed by a processor forcausing the processor to perform a method of discriminating betweencontrolled devices, comprising: generating control data having, in acontrol command for controlling controlled devices, a discriminationcode for discriminating between a controlled device to which the controlcommand is to be transmitted and other one or more controlled devices ina system; and transmitting the control data to a controlled device,wherein, when generated control data includes same data as apredetermined key code, performing a predetermined conversion of thesame data and transmitting the converted control data.